The Differences Between Organic, Non-Organic and Sustainable Gardening

It’s safe to say that as gardeners, we all care about the environment, but it can be confusing trying to understand which fertilizer or pest control will be both effective and safe for the environment. Do I need to ‘go organic’ to be a sustainable gardener? What’s the best approach for my garden environment?

In this post, Jessica Peace, trainee gardener at Dolphin Square and horticulture student, takes a look at glyphosate, and the different pest and disease controls and fertilisers, to find out if a sustainable approach to gardening can involve the use of chemicals.

Different Types of Gardeners

First, it’s probably useful to accurately define these terms:

Organic gardeners will not use ‘non-organic’ chemicals, i.e. chemicals which are ‘manmade’ or ‘synthetic’. They may use ‘plant derived’ chemicals such as ferric phosphate, which we will touch upon later.

Sustainable gardeners are not strictly ‘organic’, but strive to inflict minimum environmental impact upon their garden by exercising caution and conscience over the products they use. They may turn to non-organic controls and fertilisers as a last resort or for convenience. A sustainable approach means striving to leave the environment in the condition that you found it.

Conventional gardeners make use of fertilisers that often contain ‘non-organic’ chemicals (unless they are labelled as being derived from natural products, such as Seaweed). They may also use pesticides, most of which are also ‘non-organic’ and chemically derived unless labelled otherwise.

The Glyphosate Debate

Glyphosate is the active ingredient present in well-known herbicides such as ‘Roundup’, the use of which is a controversial topic for gardeners, farmers and politicians alike. ‘True’ organic gardeners would not use glyphosate, or in fact any manmade chemicals. Exceptions might include ferric phosphate to control slug and snail populations, and pyrethrum sprays to control aphids. Yet many gardeners still do use glyphosate – for instance, it is common when initially preparing the soil of an allotment to use an application of glyphosate for clearing perennial weeds.

Garden designer Bunny Guinness, whose voice will be familiar to Gardener’s Question Time listeners, is a big advocate of the use of glyphosate. In an article in The Telegraph, she is quoted as stating, “it is really the only effective weed-killer against perennial weeds like bindweed, ground elder and couch grass.”

Farmer Sean Sparling is the organiser of a 38 Degrees campaign, which argues for the use of glyphosate in agriculture. He maintains that glyphosate is used by sustainable farmers at the pre-drilling stage to reduce further herbicide and mechanical cultivator use. Research shows that glyphosate is mostly broken down by microbes in the soil. The problem is that this can take a long time, and although Sparling states that glyphosate breaks down into benign compounds in the soil, the evidence for this remains rather thin. Still, it is arguable that glyphosate results in fewer disturbances to the soil and ecosystems over the long term, compared with other herbicides. This explains why many ‘no-till’ farmers use glyphosate.

However, environmental bodies and political parties including The Soil Association, Garden Organic and The Green Party oppose the use of glyphosate, in both agricultural and horticultural situations. The Soil Association upholds that organic farming is more sustainable than non-organic, on the grounds that organic farming is less energy intensive and more respectful to animals and the environment.

Can sustainable gardeners use non-organic chemicals?

Scouring gardening books and chatting to other gardeners, it is apparent that many gardeners using sustainable methods condone the use of non-organic chemicals. They encourage the practice of ‘Integrated Pest Management’ (IPM), which incorporates the application of low toxic or plant derived herbicides, pesticides and fungicides.

Non-organic fertiliser is advised – although infrequently – as a way of pest and disease control, on the basis that nutrient deficiency in a plant leads to low disease resistance. Non-Organic fertilisers and pH adjusters are used for their quickness and reliability. When considering any of these options, it is advisable to purchase ‘ready to use’ products to avoid dangerous mixes.

Interestingly, in the book The Truth about Organic Gardening, Jeff Gilman draws attention to the general assumption that ‘organic’ equals ‘safe’. He rightly states that organic controls and fertilisers must still be used with caution as they can also be destructive when misused. Gilman’s book provides an extensive list of the benefits and drawbacks of both organic and non-organic methods. Another helpful resource is the website Garden Organic, which provides free, easy to understand guides and ‘organic acceptability’ ratings charts.

Regarding artificial fertiliser, Gilman suggests that ‘slow release’ fertilisers, if necessary, are the best to use. Recently, Which? Gardening threw light onto a new debate concerning this subject. The EU has proposed a ban on polymers which are contained in slow release fertilisers. Which? calls this ‘worrying news’ and claims that these fertilisers are ‘invaluable’.

However, the EU are concerned about the environmental impact of polymers, as they are not biodegradable. It’s also worth mentioning the problem of neonicotinoids, specifically acetamiprid and thiacloprid, which are often found in pesticides. According to environmental bodies, including Friends of the Earth, neonicotinoids are harming the bee and earthworm population.

One organisation who many of us turn to for gardening advice is The Royal Horticultural Society. In all instances the RHS appears to condone the use of non-organic chemicals, providing that instructions are adhered to, but emphasize that chemical use should be the last resort. RHS policy endorses an ‘integrated approach to pest, disease and weed control’, with the use of artificial fertilisers where ‘appropriate’.

To conclude, true organic gardeners will not use non-organic chemicals in their gardens, yet, they may resort to using organic derived substances. Gardeners who practise sustainable methods will often use plant derived chemicals and non-organic chemicals – avoiding neonicotinoids – but only when necessary, if other options have failed.

With all this in mind, we at Capital Gardens recommend striving for the organic or most sustainable options in our gardens where possible. However, if chemical use becomes necessary, they should be employed with with knowledge, caution and common sense.